Hi, Ms Ainey. In May guangzhou is gonna be around 30 degrees usually. July and Augest is the hotteset here. There are so many shopping centres such as Beijing road, Tee Mall, China plaza, train station, etc. I would say coming in the middle of May would be better bcs there is Canton fair during middle of April till middle of May. This is the busy time of the year that traffic is not good and hotel prices will be more expensive. If you need a tour guide or interpreter, plz feel free to drop me a line. I am local Cantonese! :)